Contamination of surfaces can cause loss of performance in a variety of applications. Bioinspired coatings based on the lotus or pitcher plants provide surface topographies that create superhydrophobic or slippery features with self‐cleaning properties. However, typical fabrication procedures often involve potentially toxic chemicals, perfluorinated compounds, nondegradable polymers, and energy‐intensive methods, with negative consequences for the environment. Here, a sustainable coating process based on renewable materials to prepare superhydrophobic and liquid‐infused coatings with minimal environmental impact is presented. A scalable spray coating protocol is used. Synthetic liquid and polymeric materials are substituted with natural drying oils, i.e., oils that react with ambient oxygen and cure to solid materials, as polymeric binder in which silica particles are partially embedded. The self‐cleaning characteristics against aqueous contaminations are investigated as a function of the drying oil used as binder. The assessment of the mechanical stability reveals the advantage of an underlying “primer layer” of the pure oil. Furthermore, it is demonstrated that oils from renewable sources can act as lubricants for the creation of slippery surfaces. The efficiency of such sustainable slippery coatings in reducing concrete adhesion points toward their applicability in real world scenarios.

To gain insight into the applicability as building blocks for optoelectronic device development, alkaline earth metal sulfides are investigated. MgS, CaS, SrS, and BaS have been systematically synthesized as colloidal particles in olelyamine. The particle sizes range from around 819 nm for MgS to 12.8 nm for CaS, 25.0 nm for SrS, and 21.6 nm for BaS. The heat-up synthesis uses commerically available precursors without complicated procedures. The structural and optical properties are investigated with X-ray diffraction, spectroscopic ellipsometry, UV–vis spectrophotometry, scanning electron microscopy, and energy dispersive X-ray spectroscopy.

Multijunction solar cells show the prospect to raise the theoretical efficiency limit of single junction solar cells by minimizing transmissive losses of large bandgap and emissive losses of lower bandgap absorber solar cells. In solar cell applications, Sb2S3 is considered an attractive absorber due to its elemental abundance, stability, and high absorption coefficient in the visible range of the solar spectrum, yet with a band gap of 1.7 eV it is transmissive for near-IR and IR photons. Using it as the top cell inside a tandem solar architecture in combination with a bottom cell employing e.g., PbS quantum dots, which have an adjustable band gap suitable for absorbing longer wavelengths, is hence a promising approach to harvest the solar spectrum more effectively. In this work, these two subcells are monolithically grown and connected in series by a poly(3,4-ethylene-dioxythiophene) polystyrene sulfonate (PEDOT:PSS)−ZnO tunnel junction as the recombination layer. We explore the surface morphology of ZnO QDs resulting from different spin coating conditions, which serve as the bottom cell’s electron transport material. Furthermore, we examine the differences in photogenerated current upon varying the PbS QDs absorber layer thickness and the electrical and optical characteristics of the tandem with respect to the standalone reference cells. This tandem architecture demonstrates an extended spectral absorption into the IR with an open-circuit potential exceeding 1.1 V and a power conversion efficiency of 5.6%, projecting above the PCE of each single-junction cell.

No abstract